Practice-clavier.



No. 689.779. I Patented Dec; 24, 1901.

v A. c. BERGMAN.

PRACTICE CLAVIER.

(Application filed Jan. 31, 1901.\ (No Model.)

- avwemtoz,

' structural conditions obtaining.

UNIT D ,STATES' PATENT. OFFICE.-

AMOS c. BERGMAN, 'o' n YoRIQN. 'Y.

'PRACTIC'E-CLAVIER.

sraclricAtrron forming part of Letters Patent No. 689,779, dated December-'24, 1901. Application filed January 31, 1901. Serial No. 45,530. 110 model.)

To all whmn it may concern.-

Be it known that I, AMOS C. BERGMAN,a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Practice-Olaviers, of which the following'is a specification.

This invention relates to practice-claviers; and it has for. its object to provide means whereby the volume and quality of sound, which is caused by the sound-producing orclick devices which are customarily embodied in practice-claviers may be enhanced.

The present invention institutes an improvement or addition with respect to sub- -ject-matter embodied in prior applications for Letters Patent filed by me, respectively, June 5, 1900, and November 14, 1900, and respecvtively bearing the Serial Nos. 19,123 and In carrying out my present invention I employ a vibration conductor or bridge, whereby the sound-producing or click device is positively connected With the base, frame,or

casing of the action of the practice-clavier, whichis thus thrown into operative vibratory association with the sound-producing or click device, whereby thetotal vibratory efiect of the impact of the striker devices upon thesound-producing or click device is altered in quality and increased in quantity, the resultant sound or click being relatively deeper, clearer, and more positive. l

In'the drawings, Figure l'is-a longitudinal sectional view of a practice-clavier embodying my presentinvention, several of the parts being broken away for clearness of illustration. Fig. 2 is a detail or fragmentary plan view ot the construction illustrated in Fig. 1.

Corresponding parts in both figures are denoted by the same reference characters.

Referring to the drawings, 1 designates the casing of a'practice-clavier, which embodies inits box-like formation a top member 2, side members 3, a rear member 4, and a bottom member 5. 'ferredand suitableform, according to' the Within the casin g are arranged the keys 6 and the soundproducing-devices or elements, two of which are preferably employed, as illustrated at 7 The casing 1 may be of any pre and 8. In thepreferred form of construction, as disclosed in the prior applications initially herein referred to, the sound-producing elements 7 and 8 are operated upon by a plurality of hammer elements,'one for and opl erated by each key, as illustrated at9. Each hammer element embodies a separate striker device 10, arranged -and adapted for operative contact with each of the sound-producing elements 7 and 8 under actuation of the respective key 6. The hammer elements and striker devices carried thereby are operated by the keys in a verticalpath of ,movement, the hammer elements being each pivotally supported at one end, as at 11. producing elements 7 and 8 are capable of vertical adjustment through the agency .of suit-able adjusting means, as at 12 and 13, re-

spectively, into and out of the paths of play. of the striker devices 10.

It will be noted that in the preferred arrangement and methodofadjustment of the sound-producing devices with respect to the paths of play of the striker devices the sound producing devices have no positive vibration;

transmitting connection withany vibratory element or device, such as the casing l, and the sound which results when the sound-producing devices are operatively engaged or struck by the striker devices is consequently thin or lacking in body, weak, and high in pitch, qualities which render the said,

result-ant sound lacking in the positive audible or acoustic properties or qualities which arejessential in the art under consideration.

In the'practice of my present invention, which provides means for overcoming the above demerits .or'negative qualities, I provide a Vibration conductor or bridge A, which is positively connected with the casingl and preferably with the-rear member 4 of the same, as at 14,and is arranged to bear positively with its free end portion a'upon the sound-producing element 7, as illustrated. A similar vibration conductor or bridge may be similarly arranged for operation with respect to the sound-producing element 8, as will be manifest, although the same is not illustrated in the drawings. Suitable tensio'nal means 15 ortensional means 16, or both, may be provided to enhance the positive bearing'of the The soundderstood by those skilled in the art to which spring 26, which is connected at one end, as

at 27, with the conductor or .tact in all the vibration conductor or bridge A upon the sound-producing element.

In the preferred form of construct-ion the conductor or bridge A consists of a relatively broad and thick body-strip 17, of wood or other suitable material, which is pivotally connected with the casing member 4 by means ofa hinge 18 and is slightly reversely curved in its opposite end portions, as at 19 and 20, respectively, whereby it arches upwardly at its end portion adjacent the casing member 4 and arches downwardly at its end portion with which-it engages with the sound-produoing element. This reversely-curved formation secures a braced relation between the casing and the sound-producing element, whereby the transmission of vibration from the latter to the former is effectively enhanced. The end portion a of the conductor or bridge ,A, which end portion contacts with the soundproducing element, is curved in its lower or operativesurfaceportion,as at 2l,andpadded, as at 22, with a covering of felt or other yielding substance, which insures an intimate coengagement of parts. By means of the hinge connection 18 the conductor or bridge Ais free to follow the sound-producing element 7 in its vertical movement of adjustment.

The tensional means 15 consists of a leaf or plate spring 23, which is connected at one end, as at 24, with the casing l ata point adjacent the point of connection 14. of the conductor or bridge A and the casing and is curved longitudinally, whereby it bears positively upon theconduotor or bridge A, preferably interm ediately of its oppositely-curved end portions 19 and 20, as at 25.

The tensional means 16 consists of a coiled bridge A and at the other end at a suitable point, as at 28, preferablywith the support 11 of the hammer element 9.

In the preferred form of construction the tensional means 15 and 16 exert their tendencies at opposite sides or points of the conductor or bridge A, and either one or both of the same may be employed at the same time, I as; desired.

It is manifest that any desired number of the conductors or bridges A may be provided for either or both of the sound-producing elements, according to the requirements to be met.

The operation and advantages of my improved means for enhancing the volume and quality of sound of sound-producing elements in practice-claviers will be readily unit appertains. The vibration conductor or bridge Ais maintained firmly in contact with the sound-producing element by the tensional means 15 or 16, or both, and follows the sound-producing element in operative conphases of adjustment of the By means of the conductor or bridge l latter.

A the casing 1 of the practice-clavier action is maintained in sympathetic vibratory relation with the sound-producing element, materially and effectively enhancing the sound produced by the engagement of the striker devices with the same. The specific re versely-curved formation of the body-strip 17 of the conductor or bridge A is advantageous with respect to firmness of operative connection of the casing with the sound-producing element and perfect vibration transmission or conduction. The curved lower surface formation of the contact end portion of the conductor or bridge A enables perfect contact of the parts at all phases of adjustment of the sound-producing element.

I do not desire to be understood as limiting myself to the specific features of formation, proportion, arrangement, and association of parts as herein described and illustrated, but reserve the right to all such modifications and variations of the same as shall fall within the scope of my invention and the terms of the following claims.

Having thus described my invention, I claim and desire to secure by Letters Patent- 1. In a practice-olavier, a movable soundproducing element, an independent vibratory element, and a vibration conductor or bridge which operates in connection with the sound-producing element and the independ ent vibratory element, said vibration con ductor or bridge being permanently and movably connected with one of said elements and arranged for operative contact with the other of said elements.

2. In a practice-clavier, a movable soundproducing element, an independent vibratory element, a vibration conductor or bridge which operates in connection with the sound producing element and the independent vibratory element, said vibration conductor or bridge being permanently and movably connected with one of said elements and arranged for operative contact with the other of said elements, and means for maintaining the vibration conductor or bridge in positive operative contact with the sound-producing element.

3. In a practice-clavier, a movable soundproducing element, an independent vibra tory element, a vibration conductor or bridge permanently pivoted to the independent vibratory element, and means for maintaining the vibration conductor or bridge in positive operative contact with the sound-producing element.

4.. In a practice-clavier, a casing, an adjustable sound-producing element arranged therein, a vibration conductor or bridge permanently pivoted to the casing and arranged for oscillation in the path of adjustment of the sound-producing element, and tensional means for normally maintaining said vibration conductor or bridge in positive operative IIO the independent vibratory element and the other of Which ends is adapted for engagement With-the sound-producing element.

In testimony whereof I have signed my 15 name, in the presence of the subscribing Witnesses, this 22d day of November, 1900.

AMOS C. BERGMAN.

\Vitnesses:

DAVID FRANKLIN, R. I. BLAKESLEE. 

